Asymmetric Synthesis of Double Bond Isomers of the Structure Proposed for Pyrinodemin A and Indication of Its Structural Revision

Abstract

Asymmetric synthesis of double bond isomers ( )-2 ([increment]15',16') and ( )-3 ([increment]14',15') ofthe structure (1) ([increment]16',17') proposed for pyrinodemin A, a cytotoxic bis-pyridine alkaloidwith a unique cis-cyclopent[c]isoxazolidine moiety from a marine sponge, has beenaccomplished. Pyrinodemin A was indicated to be a 1:1 racemic mixture of 2 fromcomparison of C18 and chiral HPLC analysis for pyrinodemin A and the syntheticcompounds as well as ESIMS data of oxidative degradation products of pyrinodemin A.